NDR's forwarding to CRM

Hello! 

My org is currently using Salesforce and we need to have our NDR's forwarded to the email set up for email-to-case. We are running into the issue that since NDR's aren't emails, but system messages, they do not follow rules created for the inbox. Is there a work around that doesn't require manual forwarding? Each day we are having to forward these undeliverable items which is tedious.

Any help is appreciated!